In recent years, with the advancement in scaling of semiconductor memory devices, a three-dimensional nonvolatile memory has been proposed which includes memory cells forming a stacked structure. In the three-dimensional nonvolatile memory, structure bodies are arranged in a two-dimensional state on a silicon layer, where each structure body includes a plurality of memory cells stacked in a height direction along the side surface of a pillar-shaped channel semiconductor film that extends in the height direction.
Further, because the three-dimensional nonvolatile memory is required to increase its capacity, the number of stacked layers of memory cells is being increased. As the number of staked layers of memory cells is increased, the channel resistance of the memory cell array becomes larger, and the current flowing through the channel for sensing the state stored in the memory cells ends up being reduced.